This invention relates to a reinforcement element for absorbing forces in concrete elements that are supported by support elements, comprising a longitudinally stable, flexible longitudinal element, which is placed in recesses in the concrete element, which recesses are disposed in such a way that the reinforcement element runs in the region of the support element in the area of the concrete element remote from the support element and runs in each case at an acute angle α toward the surface of the concrete element turned toward the support element and exits out of the concrete element and in that the end regions of the reinforcement element are anchored.
It is often necessary for reinforcements to be installed in existing structures, in particular with concrete elements that are supported by support elements, in order to be able to better absorb the arising forces. To this end there are the most diverse possibilities. For example, bores can be made in the areas to be reinforced of the concreted plate, which bores are disposed obliquely and in which tension anchors can be placed. The ends protruding beyond the concreted plate on both sides are provided with anchor heads which are supported on the respective surface of the concreted plate. The anchor heads can be designed such that the pulling element of the tension anchor can be tensioned. The bore can be filled with a grout-type material.
From EP A 2236686 (corresponds to US2011/0083386) it is also known to use a longitudinally stable, flexible band of carbon fiber-reinforced plastic, which is disposed in correspondingly made bores in the concrete element, the two ends of this band protruding on the surface of the concrete element turned toward the support and being held in anchors. This band can be tensioned through tensioning devices installed on the anchors. The bores can be subsequently grouted, whereby a very good reinforcement of the concrete element in the area of the support is achieved.
It is desirable to provide an improved reinforcement element for absorbing forces in concrete elements that are supported by support elements, which improved reinforcement element serves the purpose of absorbing large-scale stresses and which is easy to install.
According to an aspect of the invention, both end regions of the longitudinally stable, flexible longitudinal element are diverted around the respective exit edge of the recesses of the concrete element and are disposed running toward one another, and the ends of the longitudinally stable, flexible longitudinal element are held in a tensioning device and are able to be tensioned with respect to one another, so that the reinforcement element forms a closed loop.
Achieved with this design is that the two ends of the longitudinally stable, flexible longitudinal element placed in the concrete element can be put in the tensioning device in a simple way and that a simple tensioning of the longitudinal element can be achieved whereby an optimal tensioning step can be carried out. The respective forces are also thereby distributed in an optimal way.
The reinforcement element is preferably placed in the concrete element in such a way that it is disposed laterally adjacent to the support element. The reinforcement element forming a closed loop thereby comes to lie in one plane.
The longitudinally stable, flexible longitudinal element preferably has the form of a band, whose width is a multiple of the thickness, whereby an optimal diversion is achievable.
The longitudinally stable, flexible longitudinal element is preferably composed of carbon fiber-reinforced plastic. Besides the absorption of large-scale tension forces, a simple handling is also thereby obtained.
In order to be able to achieve an optimal absorption of the arising forces, the angle α is preferably in the range of 20° to 50°.
An especially simple embodiment of the invention is achieved in that the tensioning device is designed as tension lock and in that the two ends of the longitudinally stable, flexible longitudinal element are designed as loops and are held in the tension lock.
Another advantageous embodiment of the invention is in that installed in the region of the exit edges of the recesses are diversion elements, via which the respective band is diverted in a guided way, and no edges thereby arise.
In order to transfer the forces optimally of the reinforcement element in the region of the exit edge, the diversion element preferably has support surfaces, which are supported on the respective surface of the end region of the recess and/or on the surface of the concrete element.
In order to be able to further relieve these exit edges, the diversion element is attached to an end region of a supporting piece, whose other end region supports itself on the support element.
Preferably the supporting piece has the form of a plate and a plurality of diversion elements is attached to a plate, which simplifies the construction.
A further advantageous embodiment of the invention is in that the recesses made in the concrete element, through which the reinforcement element is led, are grouted with a pourable material, whereby water or the like can be prevented from penetrating into the recesses.
In order to be able to achieve an optimal absorption of forces in concrete elements that are supported by support elements in the area of these support elements, it is advantageous if a system is used comprising a plurality of such reinforcement elements, whereby preferably two reinforcement elements each are aligned parallel to one another and are disposed opposite one another and laterally with respect to the support elements.